Device including a pulley, a clutch, a retarder, and a brake, in particular for hoisting gears

ABSTRACT

The invention relates to an adjustable speed driving device. The motor 54 drives directly the inductor 1 of an eddy current clutch 51. The double bell 7-10 is keyed to the adjustable speed output shaft 2. The skirt 10 rotates round the stationary inductor 8 of the eddy current brake. A safety brake 53 is locked by the spring 15 when the electromagnet 12 is off. Application: one-piece device for handling a load on a crane or a travelling crane.

O United States Patent [191 [111 3,886,255

Noly May 27, 1975 [54] DEVICE INCLUDING A PULLEY, A 2,289,330 7/1942 Fischer et al. 310/105 X CLUTCH, A RETARDER, AND A BRAKE, IN g; i g2 8W PARTICULAR FOR HOISTING GEARS 2,806,967 9/1957 Eck et a1 310/94 X [75] Inventor: Jean Noly, La Clayette, France 2,809,312 10/1957 Eck et al 310/94 [73] Asslgnee: S IZ ZB FFJ ZBZ Lame (Val de Primary Examiner-Donovan F. Duggan Attorney, Agent, or FirmSughrue, Rothwell, Mion, [22] Filed: Apr. 20, 1973 Zinn & Macpeak [21] Appl. No.: 353,175

1 [57] ABSTRACT [30] Forei n A cation Prior" Data The invention relates to an adjustable speed driving g pp y 4 device. Apr. 21, 1972 France 149 4/72 The motor 54 drives directly the u to l of an eddy n 310 7 current clutch 51. The double bell 7-10 is keyed to g 310/9 qfif lgjz the adjustable speed output shaft 2. The skirt 10 [58] Field "310/92 l0l rotates round the stationary inductor 8 of the eddy 192/12 current brake. A safety brake 53 is locked by the I spring 15 when the electromagnet 12 is off.

[56] Ref ren es Cit d Application: one-piece device for handling a load on a UNITED STATES PATENTS 61'3116 OI a travelling crane.

2,233,060 2/1941 Parvin 310/96 1 Claim, 3 Drawing Figures PATENTEU MAY 2 7 I975 SHEET SHEET PATENTEDMAYZ? 1915 I DEVICE INCLUDING A PULLEY, A CLUTCH, A RETARDER, AND A BRAKE, IN PARTICULAR FOR HOISTING GEARS The invention relates to a device of a new type, comprising a pulley, a clutch, a retarder, and a brake, and intended to be fitted to a hoisting gear, such as a crane, a travelling crane, or an elevator.

It is known that a crane or a travelling crane must be provided with one or more winches for controlling lifting or handling cables, and one or more driving gears for angular settings. To this end, it is known to use motor units provided with coupling, braking, or speed varying devices. Such devic esare used separately, and mounting them on a crane or a travelling crane requires the provision of assembling and synchronizing systems. Furthermore, the whole assembly is subject to failures, and the maintenance thereof is difficult.

The object of the present invention is to obviate such inconveniences.

A driving device according to the invention is characterized in that it appears as a one-piece variable speed unit comprising the combination of an eddy current clutch, an eddy current retarder, and a safety brake.

The attached drawing, given by way of nonlimiting example, will enable the features of the invention to be better understood.

FIG. 1 is a partly sectional general view of a variable speed driving device according to the invention.

FIG. 2 is a front view of same, when looking in the direction of the arrow II in FIG. 1.

FIG. 3 is a similar view of a modified embodiment, wherein a single electric motor drives two variable speed systems.

The driving gear shown in FIGS. 1 and 2 includes three main members, to wit:

an eddy current clutch 51;

an eddy current retarder 52;

a safety brake 53.

The assembly is driven by an electric motor 54.

Said motor 54 runs at constant speed (such as, for instance, 1500 rpm). From the motor 54 the mechanism l-5253 according to the invention enables the output shaft 55 to be rotated at a variable speed, said shaft driving a system 56.

The eddy current clutch 51 includes:

a rotary inductor 1, adapted to rotate freely on a shaft 2, and integral with a driving pulley 3; two rings 4 for the supply of electric current to the inductor 1; a fan 5 for cooling the assembly; a double bell, the hub 6 of which is keyed to the shaft while one of its skirts, that indicated at 7, surrounds the inductor 1, around which it defines a gap.

The eddy current retarder includes:

a stationary inductor 8, integral with the casing 9 of the unit (said inductor 8 is power supplied);

a skirt 10 of the double bell; said skirt l0 surrounds the stationary inductor 8, around which it defines a gap.

The safety brake includes:

a cylindrical friction surface 11 defined on the outer wall of the skirt 7 of the double bell;

a coiled electromagnet 12, fixedly mounted on the casing 9;

a movable armature 13, capable of being attracted in the direction of the arrow 14 when the coil 12 is alive, or of being repelled in the opposite direction by a'return spring 15 when the coil 12 is off;

a braking shoe l 6 integral with the movable armature 13; said shoe :16 is provided with a friction lining 17 adapted to come and bear upon the surface 11 of the double bell 6-7-10.

Endless belts 18 connect the multi-groove pulley 3 of the unit to the pulley 19 of the driving motor 54.

The end 55 of the shaft 2 drives the driven system 56.

A tachymetric dynamo 20 is mounted on the opposite end of the shaft 2, that is, that end which corresponds to the stationary inductor 8, whereby the speed of rotation of said shaft 2 can be controlled.

The operation is as follows:

The pulley 19 of the motor 54 rotates at constant speed. It drives the inductor l of the clutch 51, at constant speed as well. The rings 4 are supplied with electric current through the brushes 2], and the electric field thus produced rotates the skirt 7 of the double bell, which transmits the motion to the system 56 through the shaft 2.

When the speed selected has been reached, the current in the inductor 1 is reduced till the torque produced balances the resisting torque: the speed of the output shaft 55 is then stable.

It is possible to modify said speed at will:

either by reducing or increasing the current in the inductor 1 of the clutch 51,

or by feeding the eddy current brake or retarder 52 at a suitable value.

Upon slowing down, the current is interrupted in the inductor 1 of the clutch, and set at a suitable value in the inductor 8 of the retarder. This arrangement is used, for instance, when the assembly is used for slowing down the fall of a load coming down under its own weight, or for slowing down the jib of a rotating crane.

Reversing the direction of rotation of the shaft 2 is obtained by reversing the motor 54.

The speed can be regulated either manually or automatically.

Said regulation is manual when acting on a double potentiometer, one branch of which supplies the inductor l of the clutch 51, while the other branch supplies the inductor 8 of the retarder 52. The electric connections are made in a way such that the current in the inductor 1 of the clutch 51 increases when the current in the inductor 8 of the retarder 52 decreases.

.The regulation is automatic if the correction of the currents in the inductors l and 8 is ensured, under electronic control, from the difference between the theoretical speed selected for the shaft 2 and the speed indication actually measured by the techymetric dynamo 20.

During all the operation steps just described, the electromagnet 12 is kept alive, that is, the brake 53 is released (lining 17 spaced from the friction surface 11).

On the other hand, when it is wanted to stop the system 56, it is only necessary to cut off the supply to the electromagnet 12: the spring then automatically ensures the locking of the skirt 7 by the friction lining 17.

The motor 54 may be used for driving a single operative system 56, as shown in FIGS. 1 and 2. It may be used as well for driving with adjustable speed two systems 156 and 256, as shown in FIG. 3. To this end, it is only necessary to make the endless belts 18 run along a triangular path between the pulleys 19and 3, and the pulley 103 corresponding-to the system 156.

In every case, the safety brake -5 3- is clamped automatically in the event of a lack of electric current.

lclaim:'-'

1. An eddy current coupling device, comprising:

a.- a rigid, generally cylindrical housing,

b. a central shaft journaled for rotation inthe housc. a double bell rigidly secured to the shaft and having a central web and cylindrical, coaxial, first and second bellskirtsintegral at their one ends with the web and axially aligned with the shaft,

d. a retarder inductor coil rigidly secured to the housing, surrounding the shaft, and substantially completely disposed within the first bell skirt and defining an air. gap therebetween,

e. a driven member rotatably mounted to the shaft,

f. a constant speed drive motor having an output shaft,

g. means drivably coupling the output shaft to the driven member,

h. a driver inductor coil rigidly secured to the driven member, rotatably secured to and surrounding the shaft, and substantially completely disposed within the second bell skirt and defining an air gap therebetween,

i. slip ring means surrounding the shaft and rotatable with the driver inductor coil for delivering electrical energy thereto, and Q j. an electromechanical safety brake mounted to the housing and including a brake shoe adapted to bear against one of the bell skirts upon actuation. 

1. An eddy current coupling device, comprising: a. a rigid, generally cylindrical housing, b. a central shaft journaled for rotation in the housing, c. a double bell rigidly secured to the shaft and having a central web and cylindrical, coaxial, first and second bell skirts integral at their one endS with the web and axially aligned with the shaft, d. a retarder inductor coil rigidly secured to the housing, surrounding the shaft, and substantially completely disposed within the first bell skirt and defining an air gap therebetween, e. a driven member rotatably mounted to the shaft, f. a constant speed drive motor having an output shaft, g. means drivably coupling the output shaft to the driven member, h. a driver inductor coil rigidly secured to the driven member, rotatably secured to and surrounding the shaft, and substantially completely disposed within the second bell skirt and defining an air gap therebetween, i. slip ring means surrounding the shaft and rotatable with the driver inductor coil for delivering electrical energy thereto, and j. an electromechanical safety brake mounted to the housing and including a brake shoe adapted to bear against one of the bell skirts upon actuation. 